US20120205759A1 - Magnetic tunnel junction with spacer layer for spin torque switched mram - Google Patents
Magnetic tunnel junction with spacer layer for spin torque switched mram Download PDFInfo
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- US20120205759A1 US20120205759A1 US13/027,342 US201113027342A US2012205759A1 US 20120205759 A1 US20120205759 A1 US 20120205759A1 US 201113027342 A US201113027342 A US 201113027342A US 2012205759 A1 US2012205759 A1 US 2012205759A1
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- 230000005291 magnetic effect Effects 0.000 title claims abstract description 95
- 125000006850 spacer group Chemical group 0.000 title claims abstract description 78
- 230000004888 barrier function Effects 0.000 claims abstract description 45
- 239000000696 magnetic material Substances 0.000 claims abstract description 43
- 239000000395 magnesium oxide Substances 0.000 claims description 22
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 22
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims description 22
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 20
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 13
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 13
- 239000011651 chromium Substances 0.000 claims description 12
- 239000000956 alloy Substances 0.000 claims description 11
- 229910045601 alloy Inorganic materials 0.000 claims description 11
- 239000010936 titanium Substances 0.000 claims description 11
- 229910052782 aluminium Inorganic materials 0.000 claims description 10
- 229910052804 chromium Inorganic materials 0.000 claims description 10
- 229910052742 iron Inorganic materials 0.000 claims description 10
- MZLGASXMSKOWSE-UHFFFAOYSA-N tantalum nitride Chemical compound [Ta]#N MZLGASXMSKOWSE-UHFFFAOYSA-N 0.000 claims description 10
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 claims description 9
- 229910052763 palladium Inorganic materials 0.000 claims description 9
- 229910003321 CoFe Inorganic materials 0.000 claims description 8
- 229910019236 CoFeB Inorganic materials 0.000 claims description 8
- 229910052697 platinum Inorganic materials 0.000 claims description 8
- 229910052707 ruthenium Inorganic materials 0.000 claims description 8
- 229910052719 titanium Inorganic materials 0.000 claims description 8
- 229910052796 boron Inorganic materials 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- 238000009792 diffusion process Methods 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 4
- 230000005290 antiferromagnetic effect Effects 0.000 claims description 3
- 230000005641 tunneling Effects 0.000 claims description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 2
- 229910017052 cobalt Inorganic materials 0.000 claims description 2
- 239000010941 cobalt Substances 0.000 claims description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 2
- 235000002639 sodium chloride Nutrition 0.000 claims description 2
- 239000011780 sodium chloride Substances 0.000 claims description 2
- 230000000593 degrading effect Effects 0.000 claims 1
- 239000010410 layer Substances 0.000 description 167
- 230000005415 magnetization Effects 0.000 description 12
- 239000002356 single layer Substances 0.000 description 10
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 9
- 239000011777 magnesium Substances 0.000 description 8
- 229910052749 magnesium Inorganic materials 0.000 description 7
- 229910052715 tantalum Inorganic materials 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 229910052720 vanadium Inorganic materials 0.000 description 6
- 229910052759 nickel Inorganic materials 0.000 description 5
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
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- 230000008025 crystallization Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
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- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/82—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by variation of the magnetic field applied to the device
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/14—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
- H01F41/30—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates for applying nanostructures, e.g. by molecular beam epitaxy [MBE]
- H01F41/302—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates for applying nanostructures, e.g. by molecular beam epitaxy [MBE] for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices
- H01F41/305—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates for applying nanostructures, e.g. by molecular beam epitaxy [MBE] for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices applying the spacer or adjusting its interface, e.g. in order to enable particular effect different from exchange coupling
- H01F41/307—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates for applying nanostructures, e.g. by molecular beam epitaxy [MBE] for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices applying the spacer or adjusting its interface, e.g. in order to enable particular effect different from exchange coupling insulating or semiconductive spacer
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N50/00—Galvanomagnetic devices
- H10N50/10—Magnetoresistive devices
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F10/00—Thin magnetic films, e.g. of one-domain structure
- H01F10/32—Spin-exchange-coupled multilayers, e.g. nanostructured superlattices
- H01F10/324—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
- H01F10/3254—Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
Definitions
- This disclosure relates generally to the field of magnetoresistive random access memory (MRAM), and more specifically to spin torque switched (STT) MRAM.
- MRAM magnetoresistive random access memory
- STT spin torque switched
- MRAM is a type of solid state memory that uses tunneling magnetoresistance (TMR) to store information.
- MRAM is made up of an electrically connected array of magnetoresistive memory elements, referred to as magnetic tunnel junctions (MTJs).
- Each MTJ includes a free layer having a magnetization direction that is variable, and a fixed layer having a magnetization direction that is invariable.
- the free layer and fixed layer each include a layer of a magnetic material, and are separated by an insulating non-magnetic tunnel barrier.
- An MTJ stores information by switching the magnetization state of the free layer. When the magnetization direction of the free layer is parallel to the magnetization direction of the fixed layer, the MTJ is in a low resistance state.
- the MTJ When the magnetization direction of the free layer is antiparallel to the magnetization direction of the fixed layer, the MTJ is in a high resistance state.
- the difference in resistance of the MTJ may be used to indicate a logical ‘1’ or ‘0’, thereby storing a bit of information.
- the TMR of an MTJ determines the difference in resistance between the high and low resistance states. A relatively high difference between the high and low resistance states facilitates read operations in the MRAM.
- the magnetization of the free layer may be changed by a spin torque switched (STT) write method, in which a write current is applied in a direction perpendicular to the film plane of the magnetic films forming the MTJ.
- the write current has a tunneling magnetoresistive effect, so as to change (or reverse) the magnetization state of the free layer of the MTJ.
- STT magnetization reversal the write current required for the magnetization reversal is determined by the current density. As the area of the surface in an MTJ on which the write current flows becomes smaller, the write current required for reversing the magnetization of the free layer of the MTJ becomes smaller. Therefore, if writing is performed with fixed current density, the necessary write current becomes smaller as the MTJ size becomes smaller.
- MTJs that include material layers that exhibit perpendicular anisotropy may be switched with a relatively low current density as compared to MTJs having in-plane magnetic anisotropy, which also lowers the necessary write current.
- PMA perpendicular anisotropy
- MTJs made using PMA materials may have a relatively low TMR because of structural and chemical incompatibility between the various material layers that comprise a PMA MTJ.
- a relatively low TMR may result in difficulty with read operations in the STT MRAM, as the difference in resistance between the high and low resistance states of the MTJs will also be relatively low.
- a magnetic tunnel junction includes first and second magnetic layers; a tunnel barrier located between the first and second magnetic layers; a first spacer layer located between the first magnetic layer and the tunnel barrier, the first spacer layer comprising a non-magnetic material; and a first interfacial layer located between the first spacer layer and the tunnel barrier.
- a magnetic tunnel junction in another aspect, includes first and second magnetic layers; a tunnel barrier located between the first and second magnetic layers; a spacer layer comprising a non-magnetic material located within the first magnetic layer.
- FIG. 1 is a schematic block diagram illustrating an embodiment of an MTJ with a spacer layer between an interfacial layer and a fixed magnetic layer.
- FIG. 2 is a schematic block diagram illustrating an embodiment of an MTJ with a spacer layer located between an interfacial layer and a free magnetic layer.
- FIG. 3 is a schematic block diagram illustrating an embodiment of an MTJ with two spacer layers.
- FIG. 4 is a schematic block diagram illustrating an embodiment of an MTJ with a spacer layer located within a fixed magnetic layer.
- FIG. 5 is a schematic block diagram illustrating an embodiment of an MTJ with a spacer layer and a synthetic antiferromagnetic (SAF) fixed layer.
- SAF synthetic antiferromagnetic
- FIG. 6 is a schematic block diagram illustrating an embodiment of a trilayer spacer layer.
- Embodiments of spacer layers for a MTJ for use in STT MRAM are provided, with exemplary embodiments being discussed below in detail.
- the spacer layer(s) act to raise the TMR of a PMA MTJ.
- a spacer layer may be inserted between a free layer and an interfacial layer of an MTJ, or between a fixed layer and an interfacial layer of the MTJ, or in any other appropriate location in the MTJ in various embodiments.
- An MTJ may include one spacer layer or multiple spacer layers in various embodiments.
- a MTJ spacer layer may include a single layer of a non-magnetic material, or a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material.
- a MTJ spacer layer may be relatively thin (e.g., 20 angstroms or less in some embodiments) to ensure a strong magnetic coupling between the interfacial layer and the free/fixed magnetic layers.
- An MTJ includes a non-magnetic, insulating tunnel barrier layer located between the fixed and free magnetic layers.
- One or more interfacial layers may be located adjacent to the tunnel barrier, between the fixed magnetic layer and the tunnel barrier or between the free magnetic layer and the tunnel barrier.
- a spacer layer that is located between an interfacial layer and a free or fixed magnetic layer may promote crystallization of the interfacial layer such that the crystalline structure of the interfacial layer lattice matches the crystalline structure of the tunnel barrier, which raises the TMR of the MTJ.
- a PMA MTJ may include a magnesium oxide (MgO) tunnel barrier, which may have a rock salt crystalline structure.
- MgO magnesium oxide
- An interfacial layer in an MTJ having an MgO tunnel barrier may also have (or can crystallize into) a body-centered cubic (BCC) crystalline structure which matches the MgO tunnel barrier.
- An interfacial layer may include materials such as iron (Fe); cobalt (Co) and Fe containing alloys; or Co, Fe, and boron (B) containing alloys.
- a spacer layer may include various non-magnetic materials, including but not limited to chromium (Cr), ruthenium (Ru), titanium nitride (TiN), Ti, vanadium (V), tantalum (Ta), tantalum nitride (TaN), aluminum (Al), magnesium (Mg), or oxides such as MgO.
- a spacer layer may reduce or block the diffusion of TMR-degrading substances to the tunnel barrier.
- TMR-degrading substances which may be present in the magnetic layers, may include but are not limited to chromium (Cr), platinum (Pt), palladium (Pd), or titanium (Ti).
- Cr chromium
- Pt platinum
- Pd palladium
- Ti titanium
- One or more additional spacer layers may be inserted into the MTJ at any appropriate location (in addition to the spacer layer locations discussed below with respect to FIGS. 1-5 ) to protect the tunnel barrier from such diffusion.
- FIG. 1 illustrates an embodiment of an MTJ 100 with a spacer layer 104 located between interfacial layer 103 and fixed magnetic layer 105 .
- Free magnetic layer 101 is located underneath tunnel barrier 102
- interfacial layer 103 is located on tunnel barrier 102 .
- Tunnel barrier 102 may include MgO
- MTJ 100 may include a PMA MTJ.
- the interfacial layer 103 may have, or can crystallize into, a BCC crystalline structure to match a tunnel barrier 102 that comprises MgO.
- the fixed magnetic layer 105 may be a single layer or a synthetic anti-ferromagnetic (SAF) layer (as discussed below with respect to FIG. 5 ) in some embodiments.
- SAF synthetic anti-ferromagnetic
- Interfacial layer 103 may include Fe; Co and Fe containing alloys; and Co, Fe, and B containing alloys.
- Free magnetic layer 101 and fixed magnetic layer 105 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, nickel (Ni), Pd, and Pt.
- the spacer layer 104 may include, but is not limited to non-magnetic materials such as Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO.
- the spacer layer 104 may include a single layer of a non-magnetic material in some embodiments, or a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect to FIG. 6 .
- FIG. 2 illustrates an embodiment of a MTJ 200 with a spacer layer 202 located between free magnetic layer 201 and interfacial layer 203 .
- Fixed magnetic layer 205 is located on top of tunnel barrier 204
- interfacial layer 203 is located on spacer layer 202 .
- Tunnel barrier 204 may include MgO
- MTJ 200 may include a PMA MTJ.
- the interfacial layer 203 may have, or can crystallize into, a BCC crystalline structure to match a tunnel barrier 204 that comprises MgO.
- Interfacial layer 203 may include Fe; Co and Fe containing alloys; and Co, Fe, and B containing alloys.
- Free magnetic layer 201 and fixed magnetic layer 205 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, Ni, Pd, and Pt.
- the fixed magnetic layer 205 may be a single layer or a SAF, as discussed below with respect to FIG. 5 , in some embodiments.
- the spacer layer 202 may include, but is not limited to, non-magnetic materials such as Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO.
- the spacer layer 202 may include a single layer of a non-magnetic material in some embodiments, or a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect to FIG. 6 .
- FIG. 3 illustrates an embodiment of a MTJ 300 with a spacer layer 302 located between free magnetic layer 301 and interfacial layer 303 , and a spacer layer 306 located between interfacial layer 307 and fixed magnetic layer 305 .
- Tunnel barrier 304 is located between interfacial layer 303 and interfacial layer 307 .
- Tunnel barrier 304 may include MgO
- MTJ 300 may include a PMA MTJ.
- the interfacial layers 303 and 307 may have, or can crystallize into, a BCC crystalline structure to match a tunnel barrier 304 that comprises MgO.
- Interfacial layers 303 and 307 may include Fe; Co and Fe containing alloys; and Co, Fe, and B containing alloys.
- Free magnetic layer 301 and fixed magnetic layer 305 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, Ni, Pd, and Pt.
- the fixed magnetic layer 305 may be a single layer or a SAF, as discussed below with respect to FIG. 5 , in some embodiments.
- the spacer layers 302 and 306 may include, but are not limited to non-magnetic materials such as Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO.
- the spacer layers 302 and 306 may include a single layer of a non-magnetic material in some embodiments, or a trilayer structure including a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect to FIG. 6 .
- a spacer layer may be inserted anywhere in an MTJ stack, as long as the magnetic coupling in the fixed magnetic layer and free magnetic layer is maintained.
- a spacer layer may be inserted within a free or fixed magnetic layer of an MTJ.
- FIG. 4 illustrates an embodiment of an MTJ 400 with a spacer layer 404 located within the fixed magnetic layer 405 .
- MTJ 400 also includes free magnetic layer 401 , interfacial layers 402 a - b , and tunnel barrier 403 .
- Tunnel barrier 403 may include MgO
- MTJ 400 may include a PMA MTJ.
- Free layer 401 and fixed layer 405 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, Ni, Pd, and Pt.
- the fixed magnetic layer 405 may be a single layer or a SAF, as discussed below with respect to FIG. 5 , in some embodiments.
- the spacer layer 404 may include, but is not limited to non-magnetic materials such as Cr, Ru, TN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO.
- the spacer layer 404 may include a single layer of a non-magnetic material in some embodiments, or a trilayer structure including a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect to FIG. 6 .
- FIG. 5 illustrates an embodiment of an MTJ 500 with a spacer layer 504 located between interfacial layer 503 and an SAF fixed magnetic layer, including layers 505 , 506 , and 507 .
- Free magnetic layer 501 is located underneath tunnel barrier 502
- interfacial layer 503 is located on tunnel barrier 502 .
- Tunnel barrier 502 may include MgO
- MTJ 500 may include a PMA MTJ.
- the interfacial layer 503 may have, or can crystallize into, a BCC crystalline structure to match a tunnel barrier 502 that comprises MgO.
- the fixed SAF magnetic layer includes two magnetic layers 505 and 507 magnetically coupled through a ruthenium spacer 506 .
- Interfacial layer 503 may include Fe; Co and Fe containing alloys; and Co, Fe, and B containing alloys.
- Free magnetic layer 501 and fixed magnetic layers 505 / 507 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, nickel (Ni), Pd, and Pt.
- the spacer layer 504 may include, but is not limited to non-magnetic materials such as Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO.
- the spacer layer 504 may include a single layer of a non-magnetic material in some embodiments, or a trilayer structure including a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect to FIG. 6 .
- Spacer layer 504 in FIG. 5 is shown for illustrative purposes only; an SAF fixed magnetic layer, such as is illustrated by layers 505 , 506 , and 506 of FIG. 5 , may be incorporated into an MTJ that includes any number of spacer layers in any appropriate location.
- FIGS. 1-5 are shown for illustrative purposes only; an MTJ may have any appropriate number of interfacial layers and spacer layers, and a spacer layer may be inserted anywhere in an MTJ stack. Additional spacer layers may be inserted to block diffusion of TMR-degrading substances (such as Cr, Pt, Pd, or Ti) to the tunnel barrier from the free or fixed magnetic layers in various embodiments.
- TMR-degrading substances such as Cr, Pt, Pd, or Ti
- FIG. 6 illustrates an embodiment of a trilayer spacer layer 600 .
- Trilayer spacer layer 500 may comprise any spacer layer in an MTJ stack, including but not limited to spacer layers 104 , 202 , 302 , 307 , 404 , or 504 .
- Magnetic layer 602 is located between non-magnetic layers 601 a - b .
- the magnetic layer 602 may crystallize to a BCC structure in some embodiments, and may include Fe, CoFe, or CoFeB in some embodiments.
- Non-magnetic layers 601 a - b may include, but are not limited to Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO.
- Trilayer spacer 600 may be 20 angstroms thick or less in some embodiments.
- the technical effects and benefits of exemplary embodiments include a PMA MTJ having a relatively high TMR, through promotion of crystallization of the interfacial layer and prevention of diffusion of TMR-degrading substances to the tunnel barrier.
Abstract
Description
- This disclosure relates generally to the field of magnetoresistive random access memory (MRAM), and more specifically to spin torque switched (STT) MRAM.
- MRAM is a type of solid state memory that uses tunneling magnetoresistance (TMR) to store information. MRAM is made up of an electrically connected array of magnetoresistive memory elements, referred to as magnetic tunnel junctions (MTJs). Each MTJ includes a free layer having a magnetization direction that is variable, and a fixed layer having a magnetization direction that is invariable. The free layer and fixed layer each include a layer of a magnetic material, and are separated by an insulating non-magnetic tunnel barrier. An MTJ stores information by switching the magnetization state of the free layer. When the magnetization direction of the free layer is parallel to the magnetization direction of the fixed layer, the MTJ is in a low resistance state. When the magnetization direction of the free layer is antiparallel to the magnetization direction of the fixed layer, the MTJ is in a high resistance state. The difference in resistance of the MTJ may be used to indicate a logical ‘1’ or ‘0’, thereby storing a bit of information. The TMR of an MTJ determines the difference in resistance between the high and low resistance states. A relatively high difference between the high and low resistance states facilitates read operations in the MRAM.
- The magnetization of the free layer may be changed by a spin torque switched (STT) write method, in which a write current is applied in a direction perpendicular to the film plane of the magnetic films forming the MTJ. The write current has a tunneling magnetoresistive effect, so as to change (or reverse) the magnetization state of the free layer of the MTJ. In STT magnetization reversal, the write current required for the magnetization reversal is determined by the current density. As the area of the surface in an MTJ on which the write current flows becomes smaller, the write current required for reversing the magnetization of the free layer of the MTJ becomes smaller. Therefore, if writing is performed with fixed current density, the necessary write current becomes smaller as the MTJ size becomes smaller. MTJs that include material layers that exhibit perpendicular anisotropy (PMA) may be switched with a relatively low current density as compared to MTJs having in-plane magnetic anisotropy, which also lowers the necessary write current. However, MTJs made using PMA materials may have a relatively low TMR because of structural and chemical incompatibility between the various material layers that comprise a PMA MTJ. A relatively low TMR may result in difficulty with read operations in the STT MRAM, as the difference in resistance between the high and low resistance states of the MTJs will also be relatively low.
- In one aspect, a magnetic tunnel junction (MTJ) includes first and second magnetic layers; a tunnel barrier located between the first and second magnetic layers; a first spacer layer located between the first magnetic layer and the tunnel barrier, the first spacer layer comprising a non-magnetic material; and a first interfacial layer located between the first spacer layer and the tunnel barrier.
- In another aspect, a magnetic tunnel junction (MTJ) includes first and second magnetic layers; a tunnel barrier located between the first and second magnetic layers; a spacer layer comprising a non-magnetic material located within the first magnetic layer.
- Additional features are realized through the techniques of the present exemplary embodiment. Other embodiments are described in detail herein and are considered a part of what is claimed. For a better understanding of the features of the exemplary embodiment, refer to the description and to the drawings.
- Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
-
FIG. 1 is a schematic block diagram illustrating an embodiment of an MTJ with a spacer layer between an interfacial layer and a fixed magnetic layer. -
FIG. 2 is a schematic block diagram illustrating an embodiment of an MTJ with a spacer layer located between an interfacial layer and a free magnetic layer. -
FIG. 3 is a schematic block diagram illustrating an embodiment of an MTJ with two spacer layers. -
FIG. 4 is a schematic block diagram illustrating an embodiment of an MTJ with a spacer layer located within a fixed magnetic layer. -
FIG. 5 is a schematic block diagram illustrating an embodiment of an MTJ with a spacer layer and a synthetic antiferromagnetic (SAF) fixed layer. -
FIG. 6 is a schematic block diagram illustrating an embodiment of a trilayer spacer layer. - Embodiments of spacer layers for a MTJ for use in STT MRAM are provided, with exemplary embodiments being discussed below in detail. The spacer layer(s) act to raise the TMR of a PMA MTJ. A spacer layer may be inserted between a free layer and an interfacial layer of an MTJ, or between a fixed layer and an interfacial layer of the MTJ, or in any other appropriate location in the MTJ in various embodiments. An MTJ may include one spacer layer or multiple spacer layers in various embodiments. A MTJ spacer layer may include a single layer of a non-magnetic material, or a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material. A MTJ spacer layer may be relatively thin (e.g., 20 angstroms or less in some embodiments) to ensure a strong magnetic coupling between the interfacial layer and the free/fixed magnetic layers.
- An MTJ includes a non-magnetic, insulating tunnel barrier layer located between the fixed and free magnetic layers. One or more interfacial layers may be located adjacent to the tunnel barrier, between the fixed magnetic layer and the tunnel barrier or between the free magnetic layer and the tunnel barrier. A spacer layer that is located between an interfacial layer and a free or fixed magnetic layer may promote crystallization of the interfacial layer such that the crystalline structure of the interfacial layer lattice matches the crystalline structure of the tunnel barrier, which raises the TMR of the MTJ. A PMA MTJ may include a magnesium oxide (MgO) tunnel barrier, which may have a rock salt crystalline structure. An interfacial layer in an MTJ having an MgO tunnel barrier may also have (or can crystallize into) a body-centered cubic (BCC) crystalline structure which matches the MgO tunnel barrier. An interfacial layer may include materials such as iron (Fe); cobalt (Co) and Fe containing alloys; or Co, Fe, and boron (B) containing alloys. A spacer layer may include various non-magnetic materials, including but not limited to chromium (Cr), ruthenium (Ru), titanium nitride (TiN), Ti, vanadium (V), tantalum (Ta), tantalum nitride (TaN), aluminum (Al), magnesium (Mg), or oxides such as MgO. A spacer layer may reduce or block the diffusion of TMR-degrading substances to the tunnel barrier. TMR-degrading substances, which may be present in the magnetic layers, may include but are not limited to chromium (Cr), platinum (Pt), palladium (Pd), or titanium (Ti). One or more additional spacer layers may be inserted into the MTJ at any appropriate location (in addition to the spacer layer locations discussed below with respect to
FIGS. 1-5 ) to protect the tunnel barrier from such diffusion. -
FIG. 1 illustrates an embodiment of anMTJ 100 with aspacer layer 104 located betweeninterfacial layer 103 and fixedmagnetic layer 105. Freemagnetic layer 101 is located underneathtunnel barrier 102, andinterfacial layer 103 is located ontunnel barrier 102.Tunnel barrier 102 may include MgO, and MTJ 100 may include a PMA MTJ. Theinterfacial layer 103 may have, or can crystallize into, a BCC crystalline structure to match atunnel barrier 102 that comprises MgO. The fixedmagnetic layer 105 may be a single layer or a synthetic anti-ferromagnetic (SAF) layer (as discussed below with respect toFIG. 5 ) in some embodiments.Interfacial layer 103 may include Fe; Co and Fe containing alloys; and Co, Fe, and B containing alloys. Freemagnetic layer 101 and fixedmagnetic layer 105 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, nickel (Ni), Pd, and Pt. Thespacer layer 104 may include, but is not limited to non-magnetic materials such as Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO. Thespacer layer 104 may include a single layer of a non-magnetic material in some embodiments, or a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect toFIG. 6 . -
FIG. 2 illustrates an embodiment of aMTJ 200 with aspacer layer 202 located between freemagnetic layer 201 andinterfacial layer 203. Fixedmagnetic layer 205 is located on top oftunnel barrier 204, andinterfacial layer 203 is located onspacer layer 202.Tunnel barrier 204 may include MgO, and MTJ 200 may include a PMA MTJ. Theinterfacial layer 203 may have, or can crystallize into, a BCC crystalline structure to match atunnel barrier 204 that comprises MgO.Interfacial layer 203 may include Fe; Co and Fe containing alloys; and Co, Fe, and B containing alloys. Freemagnetic layer 201 and fixedmagnetic layer 205 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, Ni, Pd, and Pt. The fixedmagnetic layer 205 may be a single layer or a SAF, as discussed below with respect toFIG. 5 , in some embodiments. Thespacer layer 202 may include, but is not limited to, non-magnetic materials such as Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO. Thespacer layer 202 may include a single layer of a non-magnetic material in some embodiments, or a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect toFIG. 6 . -
FIG. 3 illustrates an embodiment of aMTJ 300 with aspacer layer 302 located between freemagnetic layer 301 andinterfacial layer 303, and aspacer layer 306 located betweeninterfacial layer 307 and fixedmagnetic layer 305.Tunnel barrier 304 is located betweeninterfacial layer 303 andinterfacial layer 307.Tunnel barrier 304 may include MgO, andMTJ 300 may include a PMA MTJ. Theinterfacial layers tunnel barrier 304 that comprises MgO.Interfacial layers magnetic layer 301 and fixedmagnetic layer 305 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, Ni, Pd, and Pt. The fixedmagnetic layer 305 may be a single layer or a SAF, as discussed below with respect toFIG. 5 , in some embodiments. The spacer layers 302 and 306 may include, but are not limited to non-magnetic materials such as Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO. The spacer layers 302 and 306 may include a single layer of a non-magnetic material in some embodiments, or a trilayer structure including a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect toFIG. 6 . - In addition to the MTJ embodiments described above with respect to
FIGS. 1-3 , a spacer layer may be inserted anywhere in an MTJ stack, as long as the magnetic coupling in the fixed magnetic layer and free magnetic layer is maintained. For example, a spacer layer may be inserted within a free or fixed magnetic layer of an MTJ.FIG. 4 illustrates an embodiment of anMTJ 400 with aspacer layer 404 located within the fixedmagnetic layer 405.MTJ 400 also includes freemagnetic layer 401, interfacial layers 402 a-b, andtunnel barrier 403.Tunnel barrier 403 may include MgO, andMTJ 400 may include a PMA MTJ.Free layer 401 and fixedlayer 405 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, Ni, Pd, and Pt. The fixedmagnetic layer 405 may be a single layer or a SAF, as discussed below with respect toFIG. 5 , in some embodiments. Thespacer layer 404 may include, but is not limited to non-magnetic materials such as Cr, Ru, TN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO. Thespacer layer 404 may include a single layer of a non-magnetic material in some embodiments, or a trilayer structure including a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect toFIG. 6 . -
FIG. 5 illustrates an embodiment of anMTJ 500 with aspacer layer 504 located betweeninterfacial layer 503 and an SAF fixed magnetic layer, includinglayers magnetic layer 501 is located underneathtunnel barrier 502, andinterfacial layer 503 is located ontunnel barrier 502.Tunnel barrier 502 may include MgO, andMTJ 500 may include a PMA MTJ. Theinterfacial layer 503 may have, or can crystallize into, a BCC crystalline structure to match atunnel barrier 502 that comprises MgO. The fixed SAF magnetic layer includes twomagnetic layers ruthenium spacer 506.Interfacial layer 503 may include Fe; Co and Fe containing alloys; and Co, Fe, and B containing alloys. Freemagnetic layer 501 and fixedmagnetic layers 505/507 may include multilayers of various magnetic materials, such as Co, CoFe, CoFeB, nickel (Ni), Pd, and Pt. Thespacer layer 504 may include, but is not limited to non-magnetic materials such as Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO. Thespacer layer 504 may include a single layer of a non-magnetic material in some embodiments, or a trilayer structure including a relatively thin layer of a magnetic material located between two relatively thin layers of a non-magnetic material in other embodiments, as discussed below with respect toFIG. 6 .Spacer layer 504 inFIG. 5 is shown for illustrative purposes only; an SAF fixed magnetic layer, such as is illustrated bylayers FIG. 5 , may be incorporated into an MTJ that includes any number of spacer layers in any appropriate location. -
FIGS. 1-5 are shown for illustrative purposes only; an MTJ may have any appropriate number of interfacial layers and spacer layers, and a spacer layer may be inserted anywhere in an MTJ stack. Additional spacer layers may be inserted to block diffusion of TMR-degrading substances (such as Cr, Pt, Pd, or Ti) to the tunnel barrier from the free or fixed magnetic layers in various embodiments. -
FIG. 6 illustrates an embodiment of atrilayer spacer layer 600.Trilayer spacer layer 500 may comprise any spacer layer in an MTJ stack, including but not limited tospacer layers Magnetic layer 602 is located between non-magnetic layers 601 a-b. Themagnetic layer 602 may crystallize to a BCC structure in some embodiments, and may include Fe, CoFe, or CoFeB in some embodiments. Non-magnetic layers 601 a-b may include, but are not limited to Cr, Ru, TiN, Ti, V, Ta, TaN, Al, Mg, or oxides such as MgO.Trilayer spacer 600 may be 20 angstroms thick or less in some embodiments. - The technical effects and benefits of exemplary embodiments include a PMA MTJ having a relatively high TMR, through promotion of crystallization of the interfacial layer and prevention of diffusion of TMR-degrading substances to the tunnel barrier.
- The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
- The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
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Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20140015079A1 (en) * | 2011-05-10 | 2014-01-16 | Magic Technologies, Inc. | Co/Ni Multilayers with Improved Out-of-Plane Anisotropy for Magnetic Device Applications |
US8866207B2 (en) | 2011-04-25 | 2014-10-21 | International Business Machines Corporation | Magnetic stacks with perpendicular magnetic anisotropy for spin momentum transfer magnetoresistive random access memory |
WO2016007126A1 (en) * | 2014-07-07 | 2016-01-14 | Intel Corporation | Spin-transfer torque memory (sttm) devices having magnetic contacts |
WO2016137171A1 (en) * | 2015-02-23 | 2016-09-01 | 고려대학교 산학협력단 | Multilayer magnetic thin film stack and non-volatile memory device including same |
US9564580B2 (en) | 2014-12-29 | 2017-02-07 | International Business Machines Corporation | Double synthetic antiferromagnet using rare earth metals and transition metals |
US9666640B2 (en) | 2015-03-16 | 2017-05-30 | Globalfoundries Singapore Pte. Ltd. | High thermal budget magnetic memory |
US20170155039A1 (en) * | 2015-11-30 | 2017-06-01 | SK Hynix Inc. | Electronic device |
US9876163B2 (en) | 2015-03-05 | 2018-01-23 | Globalfoundries Singapore Pte. Ltd. | Magnetic memory with tunneling magnetoresistance enhanced spacer layer |
US10297745B2 (en) | 2015-11-02 | 2019-05-21 | Globalfoundries Singapore Pte. Ltd. | Composite spacer layer for magnetoresistive memory |
US10651369B2 (en) * | 2010-06-04 | 2020-05-12 | Tohoku University | Magnetoresistive element and magnetic memory |
US10840297B2 (en) | 2015-03-27 | 2020-11-17 | Globalfoundries Singapore Pte. Ltd. | Storage layer for magnetic memory with high thermal stability |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8508006B2 (en) * | 2011-05-10 | 2013-08-13 | Magic Technologies, Inc. | Co/Ni multilayers with improved out-of-plane anisotropy for magnetic device applications |
US8852760B2 (en) * | 2012-04-17 | 2014-10-07 | Headway Technologies, Inc. | Free layer with high thermal stability for magnetic device applications by insertion of a boron dusting layer |
US9634237B2 (en) | 2014-12-23 | 2017-04-25 | Qualcomm Incorporated | Ultrathin perpendicular pinned layer structure for magnetic tunneling junction devices |
US9337415B1 (en) | 2015-03-20 | 2016-05-10 | HGST Netherlands B.V. | Perpendicular spin transfer torque (STT) memory cell with double MgO interface and CoFeB layer for enhancement of perpendicular magnetic anisotropy |
US9831419B2 (en) | 2015-07-13 | 2017-11-28 | Western Digital Technologies, Inc. | Magnetoresistive device with laminate insertion layer in the free layer |
US9564581B1 (en) | 2015-11-20 | 2017-02-07 | HGST Netherlands B.V. | Magnetoresistive effect devices having enhanced magnetic anisotropy |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6166948A (en) * | 1999-09-03 | 2000-12-26 | International Business Machines Corporation | Magnetic memory array with magnetic tunnel junction memory cells having flux-closed free layers |
US20050186357A1 (en) * | 2004-02-23 | 2005-08-25 | Tdk Corporation | Method for manufacturing magnetic recording medium |
US7092284B2 (en) * | 2004-08-20 | 2006-08-15 | Infineon Technologies Ag | MRAM with magnetic via for storage of information and field sensor |
US20060204792A1 (en) * | 2004-04-06 | 2006-09-14 | Hiroshi Osawa | Magnetic recording medium, production process therefor, and magnetic recording and reproducing apparatus |
US20070278547A1 (en) * | 2006-05-31 | 2007-12-06 | Pietambaram Srinivas V | MRAM synthetic anitferomagnet structure |
US20080231998A1 (en) * | 2006-09-29 | 2008-09-25 | Masatoshi Yoshikawa | Magnetoresistive effect device and magnetic random access memory using the same |
US20100078741A1 (en) * | 2008-09-29 | 2010-04-01 | Seagate Technology Llc | Stram with compensation element |
US20100096716A1 (en) * | 2007-02-12 | 2010-04-22 | Yadav Technology Inc. | Spin-transfer torque magnetic random access memory having magnetic tunnel junction with perpendicular magnetic anisotropy |
US20100109109A1 (en) * | 2008-10-31 | 2010-05-06 | Industrial Technology Research Institute | Magnetic memory element utilizing spin transfer switching |
US20100178528A1 (en) * | 2007-06-19 | 2010-07-15 | Canon Anelva Corporation | Tunnel magnetoresistive thin film and magnetic multilayer film formation apparatus |
US20110062538A1 (en) * | 2007-10-11 | 2011-03-17 | Everspin Technologies, Inc. | Magnetic element having reduced current density |
US20110064969A1 (en) * | 2009-09-15 | 2011-03-17 | Grandis Inc. | Magnetic Element Having Perpendicular Anisotropy With Enhanced Efficiency |
US20110159316A1 (en) * | 2009-12-31 | 2011-06-30 | Industrial Technology Research Institute | Magnetoresistive device with perpendicular magnetization |
US20120063218A1 (en) * | 2010-09-14 | 2012-03-15 | Avalanche Technology, Inc. | Spin-transfer torque magnetic random access memory with perpendicular magnetic anisotropy multilayers |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6845038B1 (en) | 2003-02-01 | 2005-01-18 | Alla Mikhailovna Shukh | Magnetic tunnel junction memory device |
US7313013B2 (en) | 2004-11-18 | 2007-12-25 | International Business Machines Corporation | Spin-current switchable magnetic memory element and method of fabricating the memory element |
JP4496189B2 (en) | 2006-09-28 | 2010-07-07 | 株式会社東芝 | Magnetoresistive element and magnetoresistive random access memory |
US8063709B2 (en) | 2007-02-21 | 2011-11-22 | Centre National De La Recherche Scientifique | Spin-transfer torque oscillator |
US7663131B2 (en) | 2007-03-08 | 2010-02-16 | Magic Technologies, Inc. | SyAF structure to fabricate Mbit MTJ MRAM |
JP4738395B2 (en) | 2007-09-25 | 2011-08-03 | 株式会社東芝 | Magnetoresistive element and magnetic random access memory using the same |
-
2011
- 2011-02-15 US US13/027,342 patent/US8492859B2/en active Active
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6166948A (en) * | 1999-09-03 | 2000-12-26 | International Business Machines Corporation | Magnetic memory array with magnetic tunnel junction memory cells having flux-closed free layers |
US20050186357A1 (en) * | 2004-02-23 | 2005-08-25 | Tdk Corporation | Method for manufacturing magnetic recording medium |
US20060204792A1 (en) * | 2004-04-06 | 2006-09-14 | Hiroshi Osawa | Magnetic recording medium, production process therefor, and magnetic recording and reproducing apparatus |
US7092284B2 (en) * | 2004-08-20 | 2006-08-15 | Infineon Technologies Ag | MRAM with magnetic via for storage of information and field sensor |
US20070278547A1 (en) * | 2006-05-31 | 2007-12-06 | Pietambaram Srinivas V | MRAM synthetic anitferomagnet structure |
US20080231998A1 (en) * | 2006-09-29 | 2008-09-25 | Masatoshi Yoshikawa | Magnetoresistive effect device and magnetic random access memory using the same |
US20100096716A1 (en) * | 2007-02-12 | 2010-04-22 | Yadav Technology Inc. | Spin-transfer torque magnetic random access memory having magnetic tunnel junction with perpendicular magnetic anisotropy |
US20100178528A1 (en) * | 2007-06-19 | 2010-07-15 | Canon Anelva Corporation | Tunnel magnetoresistive thin film and magnetic multilayer film formation apparatus |
US20110062538A1 (en) * | 2007-10-11 | 2011-03-17 | Everspin Technologies, Inc. | Magnetic element having reduced current density |
US20100078741A1 (en) * | 2008-09-29 | 2010-04-01 | Seagate Technology Llc | Stram with compensation element |
US20100109109A1 (en) * | 2008-10-31 | 2010-05-06 | Industrial Technology Research Institute | Magnetic memory element utilizing spin transfer switching |
US20110064969A1 (en) * | 2009-09-15 | 2011-03-17 | Grandis Inc. | Magnetic Element Having Perpendicular Anisotropy With Enhanced Efficiency |
US20110159316A1 (en) * | 2009-12-31 | 2011-06-30 | Industrial Technology Research Institute | Magnetoresistive device with perpendicular magnetization |
US20120063218A1 (en) * | 2010-09-14 | 2012-03-15 | Avalanche Technology, Inc. | Spin-transfer torque magnetic random access memory with perpendicular magnetic anisotropy multilayers |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10651369B2 (en) * | 2010-06-04 | 2020-05-12 | Tohoku University | Magnetoresistive element and magnetic memory |
US8866207B2 (en) | 2011-04-25 | 2014-10-21 | International Business Machines Corporation | Magnetic stacks with perpendicular magnetic anisotropy for spin momentum transfer magnetoresistive random access memory |
US8878323B2 (en) * | 2011-05-10 | 2014-11-04 | Headway Technologies, Inc. | Co/Ni multilayers with improved out-of-plane anisotropy for magnetic device applications |
US20140015079A1 (en) * | 2011-05-10 | 2014-01-16 | Magic Technologies, Inc. | Co/Ni Multilayers with Improved Out-of-Plane Anisotropy for Magnetic Device Applications |
US10158065B2 (en) | 2014-07-07 | 2018-12-18 | Intel Corporation | Spin-transfer torque memory (STTM) devices having magnetic contacts |
WO2016007126A1 (en) * | 2014-07-07 | 2016-01-14 | Intel Corporation | Spin-transfer torque memory (sttm) devices having magnetic contacts |
US10580973B2 (en) | 2014-07-07 | 2020-03-03 | Intel Corporation | Spin-transfer torque memory (STTM) devices having magnetic contacts |
US9564580B2 (en) | 2014-12-29 | 2017-02-07 | International Business Machines Corporation | Double synthetic antiferromagnet using rare earth metals and transition metals |
WO2016137171A1 (en) * | 2015-02-23 | 2016-09-01 | 고려대학교 산학협력단 | Multilayer magnetic thin film stack and non-volatile memory device including same |
US9876163B2 (en) | 2015-03-05 | 2018-01-23 | Globalfoundries Singapore Pte. Ltd. | Magnetic memory with tunneling magnetoresistance enhanced spacer layer |
US9923137B2 (en) | 2015-03-05 | 2018-03-20 | Globalfoundries Singapore Pte. Ltd. | Magnetic memory with tunneling magnetoresistance enhanced spacer layer |
US9666640B2 (en) | 2015-03-16 | 2017-05-30 | Globalfoundries Singapore Pte. Ltd. | High thermal budget magnetic memory |
US10840297B2 (en) | 2015-03-27 | 2020-11-17 | Globalfoundries Singapore Pte. Ltd. | Storage layer for magnetic memory with high thermal stability |
US10297745B2 (en) | 2015-11-02 | 2019-05-21 | Globalfoundries Singapore Pte. Ltd. | Composite spacer layer for magnetoresistive memory |
US10217932B2 (en) * | 2015-11-30 | 2019-02-26 | SK Hynix Inc. | Electronic device |
US20170155039A1 (en) * | 2015-11-30 | 2017-06-01 | SK Hynix Inc. | Electronic device |
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